Survey reveals the likelihood that current Republican presidential front-runner Donald Trump will secure the party nomination has fallen by 23 percentage points.

The probability that Republican front-runner Donald Trump will win his party's presidential nomination dropped sharply in the past week while the likelihood of a brokered convention to potentially choose another candidate rose, according to online predictions market Predictit.

Trump's probability of winning the nomination fell to 44 percent on Friday from 67 percent a week ago, according to the website, which is run by Victoria University in Wellington, New Zealand. For Republican rival Ted Cruz, a U.S. Senator from Texas, it rose to 34 percent from 14 percent during the same period.

The probability that the Republicans will have a brokered convention to decide the nominee for the Nov. 8 election jumped to 69 percent from 43 percent a week ago, according to PredictIt, an online predictions market where users place money on who they think will win the election. Many users are from the United States.

Celebrity businessman Trump is facing pressure to take a more serious approach to his presidential campaign from supporters worried that a string of recent missteps and controversial comments may do lasting damage.